Sepsis is an often fatal clinical syndrome that develops after infection or injury. Sepsis is the most frequent cause of mortality in hospitalized patients. Experimental models of gram negative sepsis based on administration of bacterial endotoxin (lipopolysaccharide, LPS) have led to an improved understanding of the pathogenic mechanisms of lethal sepsis and conditions related to sepsis by virtue of the activation of a common underlying inflammatory cytokine cascade. This cascade of host-response mediators includes TNF, IL-1, PAF and other macrophage-derived factors that have been widely studied as acute, early mediators of eventual lethality in severe endotoxemia (Zhang and Tracey, In The Cytokine Handbook, 3rd ed. Ed. Thompson (Academic Press Limited, USA). 515–547, 1998).
Unfortunately, therapeutic approaches based on inhibiting these individual “early” mediators of endotoxemia have met with only limited success in large prospective clinical trials against sepsis in human patients. It is possible to infer from these disappointing results that later-appearing factors in the host response might critically determine pathogenesis and/or lethality in sepsis and related disorders. Accordingly, there is a need to discover such putative “late” mediators necessary and/or sufficient for part or all of the extensive multisystem pathogenesis, or for the lethality, of severe endotoxemia, particularly as endotoxemia is representative of clinical sepsis and related clinical disorders.
HMG1 is a 30 kDa chromosomal nucleoprotein belonging to the burgeoning high mobility group (HMG) of non-histone chromatin-associated proteins. As a group, the HMG proteins recognize unique DNA structures and have been implicated in diverse cellular functions, including determination of nucleosome structure and stability, as well as in transcription and/or replication. The HMG proteins were first characterized by Johns and Goodwin as chromatin components with a high electrophoretic mobility in polyacrylamide gels (see in The HMG Chromosomal Proteins, E. W. Johns, Academic Press, London, 1982). Higher eukaryotes exhibit three families of HMG proteins: the HMG-1/-2 family, the HMG-14/-17 family and the HMG-I/-Y family. Although the families are distinguishable by size and DNA-binding properties, they are similar in their physical properties. HMG proteins are highly conserved across species, ubiquitously distributed and highly abundant, and are extractable from chromatin in 0.35 M NaCl and are soluble in 5% perchloric or trichloroacetic acid. Generally, HMG proteins are thought to bend DNA and facilitate binding of various transcription factors to their cognate sequences, including for instance, progesterone receptor, estrogen receptor, HOX proteins, and Oct1, Oct2 and Oct6. Recently, it has become apparent that a large, highly diverse group of proteins including several transcription factors and other DNA-interacting proteins, contain one or more regions similar to HMG1, and this feature has come to be known as the HMG1 box or HMG1 domain. cDNAs coding for HMG1 have been cloned from human, rat, trout, hamster, pig and calf cells, and HMG1 is believed to be abundant in all vertebrate cell nuclei. The protein is highly conserved with interspecies sequence identities in the 80% range. In chromatin, HMG1 binds to linker DNA between nucleosomes and to a variety of non-β-DNA structures such as palindromes, cruciforms and stem-loop structures, as well as cisplatin-modified DNA. DNA binding by HMG1 is generally believed to be sequence insensitive. HMG1 is most frequently prepared from washed nuclei or chromatin, but the protein has also been detected in the cytoplasm. (Reviewed in Landsman and Bustin, BioEssays 15:539–546, 1993; Baxevanis and Landsman, Nucleic Acids Research 23:514–523, 1995). To date, no link has been established between the HMG proteins and any clinical condition or disease.
HMG1 has been alternatively identified as a heparin-binding protein abundantly expressed in developing brain and dubbed “anphoterin” for its highly dipolar sequence, comprising two internal repeats of a positively charged domain of about 80 amino acids (the HMG1 box) and an acidic C-terminal domain containing a stretch of approximately 30 continuous glutamic or aspartic acid residues. Amphoterin/HMG1 has been localized to the outer surface of the plasma membranes of epithelial, and especially neuronal cells, where it has been specifically localized to the filipodia of neural cells. Inhibition studies have suggested that amphoterin/HMG1 is required for process (neurite) extension and amphoterin/HMG1 also may be involved in neuron-glia interactions (Merenmies et al., J. Biol. Chem. 266:16722–16729, 1991; Merenmies et al., J. Biol. Chem. 266:16722–16729, 1991; Milev et al., J. Biol. Chem. 273:6998–7005, 1998; and Salmivirta et al., Exp. Cell Res. 200:444–451, 1992). Amphoterin/HMG1 can be released from murine erythroleukemia cells after stimulation with the chemical inducer hexamethylenebisacetamide (Melloni et al., Biochem, Biophys. Res. Commun. 210:82–89, 1995). Previous study suggested that the gene product of the HMG1 gene functions as a differentiation enhancing factor by stimulating α-PKC (Melloni et al., Biochem. Biophys. Res. Commun. 210:82–89, 1995; and Melloni et al., FEBS Lett. 368:466–470, 1995).
The HMG1 gene product has been shown to interact with plasminogen and tissue-type plasminogen activator (t-PA) and effectively enhance plasmin generation at the cell surface, a system that is known to play a role in extracellular proteolysis during cell invasion and tissue remodeling. Amphoterin/HMG1 has also been shown to interact with the receptor of advanced glycosylation end products (RAGE) (Mohan et al., Biochem. Biophys. Res. Commun. 182:689–696, 1992; Yamawaki et al., J. Neurosci. Res. 44:586–593, 1996; Salmivirta et al., Exp. Cell Res. 200:444–451, 1992; and Vassalli et al., J. Clin. Invest. 88:1067–1072, 1991), (Redlitz and Plow, Baillieres Clin. Haematol. 8:313–327, 1995; and Parkkinen et al., J. Biol. Chem. 266:16730–16735, 1991).
There is a longstanding need in the art to discover improved agents that can prevent the cytokine-mediated inflammatory cascade and have therapeutic activity in a large variety of cytokine-mediated inflammatory diseases. The present invention was made during the course of investigative research to identify agents that mediate toxicity, pathogenesis and/or lethality in sepsis and other disorders related by a common activation of the inflammatory cytokine cascade.
Diseases and conditions mediated by the inflammatory cytokine cascade are numerous. Such conditions include the following grouped in disease categories:                Systemic Inflammatory Response Syndrome, which includes:                    Sepsis syndrome                            Gram positive sepsis                Gram negative sepsis                Culture negative sepsis                Fungal sepsis                Neutropenic fever                Urosepsis                                    Meningococcemia            Trauma hemorrhage            Hums            Ionizing radiation exposure            Acute pancreatitis            Adult respiratory distress syndrome (ARDS)                        Reperfusion Injury, which includes                    Post-pump syndrome            Ischemia-reperfusion injury                        Cardiovascular Disease, which includes                    Cardiac stun syndrome            Myocardial infarction            Congestive heart failure                        Infectious Disease, which includes                    HIV infection/HIV neuropathy            Meningitis            Hepatitis            Septic arthritis            Peritonitis            Pneumonia Epiglottitis            E. coli 0157:H7                            Hemolytic uremic syndrome/thrombolytic thrombocytopenic purpura                Malaria                Dengue hemorrhagic fever                Leishmaniasis                Leprosy                Toxic shock syndrome                Streptococcal myositis                Gas gangrene                Mycobacterium tuberculosis                Mycobaclerium aviun intracellulare                Pneumocystis carinii pneumonia                Pelvic inflammatory disease                Orchitis/epidydimitis                Legionella                Lyme disease                Influenza A                Epstein-Barr Virus                Viral associated hemiaphagocytic syndrome                Viral encephalitis/aseptic meningitis                                                Obstetrics/Gynecology, including:                    Premature labor            Miscarriage            Infertility                        Inflammatory Disease/Autoimmunity, which includes:                    Rheumatoid arthritis/seronegative arthropathies            Osteoarthritis            Inflammatory bowel disease            Systemic lupus erythematosis            Iridoeyelitis/uveitistoptic neuritis            Idiopathic pulmonary fibrosis            Systemic vasculitis/Wegener's gramilornatosis            Sarcoidosis            Orchitis/vasectomy reversal procedures                        Allergic/Atopic Diseases, which includes:                    Asthma            Allergic rhinitis            Eczema            Allergic contact dermatitis            Allergic conjunctivitis            Hypersensitivity pneumonitis                        Malignancy, which includes:                    ALL            AML            CML            CLL            Hodgkin's disease, non-Hodgkin's lymphoma            Kaposi's sarcoma            Colorectal carcinoma            Nasopharyngeal carcinoma            Malignant histiocytosis            Paraneoplastic syndrome/hypercalcemia of malignancy                        Transplants, including:                    Organ transplant rejection            Graft-versus-host disease                        Cachexia        Congenital, which includes:                    Cystic fibrosis            Familial hematophagocytic lymphohistiocytosis            Sickle cell anemia                        Dermatologic, which includes:                    Psoriasis            Alopecia                        Neurologic, which includes:                    Multiple sclerosis            Migraine headache                        Renal, which includes:                    Nephrotic syndrome            Hemodialysis            Uremia                        Toxicity, which includes:                    OKT3 therapy            Anti-CD3 therapy            Cytokine therapy            Chemotherapy            Radiation therapy            Chronic salicylate intoxication                        Metabolic/Idiopathic, which includes:                    Wilson's disease            Hemachromatosis            Alpha-1 antitrypsin deficiency            Diabetes            Hashimoto's thyroiditis            Osteoporosis            Hypothalamic-pituitary-adrenal axis evaluation            Primary biliary cirrhosis                        